| 摘要 |
<p>An apparatus is provided comprising a first tubular having an inside surface and outside surface defining an outside diameter; a second tubular concentric with the first tubular, the second tubular having an inside surface defining an inside diameter greater than the outside diameter of the first tubular, an outside surface, and a longitudinal axis; a plurality of spacers between the first and second tubulars, each spacer having a longitudinal axis parallel to the longitudinal axis of the second tubular, wherein at least one spacer is hollow; and at least one data sensing device and/or at least one data collecting device and/or at least one data transmitting device is carried within the at least one hollow spacer.</p> |
